The present invention relates generally to the field of information technology storage systems, and more specifically to interaction with storage area networks through multipath communications.
In information technology (IT) systems with storage area network (SAN) storage, multipath software is sometimes used by a host system to send input/output (I/O) requests to the storage system. In multipath I/O, multiple data paths are provided between a host computer system and a storage system, through buses, controllers, switches, and bridges connecting them. Multipath software can send I/O requests to the storage system via one or more of the multiple I/O paths, to provide features including load balancing, and path management.
A volume in SAN storage (SAN disk) is made up of multiple physical areas, herein referred to as physical domains. Different physical domains handle I/O requests independently, and without impact to other physical domains. The physical domains may have differing I/O workloads that shift over time (sometimes herein referred to as pressures).